One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(6,8)(9,10)(11,14)(12,17)(13,16)(15,20)(18,21)(19,23)(22,24)(25,26,31,34)(27,32,29,28)(30,33,39,38)(35,40,37,36)(3,7)(6,8)(10,11)(15,17)(16,18)(22,23)(25,27,31,29)(26,28,34,32)(30,35,39,37)(33,36,38,40)(1,2,5,4)(3,6,7,8)(9,10,14,11)(12,15,20,17)(13,16,21,18)(19,22,24,23)(25,28,31,32)(26,27,34,29)(30,36,39,40)(33,35,38,37)(1,3,5,7)(2,6,4,8)(9,11,14,10)(12,17,20,15)(13,18,21,16)(19,23,24,22)(25,26)(27,28)(29,32)(30,38)(31,34)(33,39)(35,40)(36,37)(1,4,5,2)(3,8,7,6)(9,12,14,20)(10,15,11,17)(13,19,21,24)(16,22,18,23)(25,29,31,27)(26,32,34,28)(30,37,39,35)(33,40,38,36)(9,13,14,21)(10,16,11,18)(12,19,20,24)(15,22,17,23)(25,30)(26,33)(27,35)(28,36)(29,37)(31,39)(32,40)(34,38)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.